1. Field of the Invention
The invention relates to a drive for a pilger cold-rolling mill with mass and torque balancing, where a crank is driven and rotates around a vertical axis and is connected to a roller frame horizontally guided via a coupler in a guide and where the coupler, with its total mass, assumes a balancing of moments and where the crank, with its total mass, assumes the mass balancing.
2. Brief Description of the Background of the Invention Including Prior Art
A pilger cold-rolling mill of the kine recited is known from the German Patent Application Laid Out DE-AS No. 2,740,729, where the crank drive is disposed staggered to the side relative to the rolling mill. The crank is thereby connected via a crankshaft throw with the balancing mass disposed above the crank drive for balancing of moments. The balancing mass is disposed phase-shifted relative to the crank. The reciprocating motion back and forth is made possible by a parallel guide. The roller mill is coupled via a long connecting rod which is supported on one side at the crankshaft throw.
The roller frame can be disposed immediately above the crank drive and the coupler can be supported immediately on the crank pin. The coupler can take care of the momentum balancing with its total mass and the crank can take care with its total mass of the balancing of masses. According to this method, the balancing of the masses reduces the mass forces, comprising the forces of inertia and the centrifugal forces, which act via the casing on the foundation and the balancing of momentum reduces the drive torques for the acceleration of the back and forth moving frame mass.
According to these methods, there remains a moment of inertia relative to a horizontal axis, which acts at a right angle relative to the direction of motion of the roller stand. The mass moment torque is generated because the force of inertia engaging at the center of gravity of the roller stand and the centrifugal force of the mass MA engaging in the virtual engagement point, i.e. the center of gravity, are in fact of equal size but are not disposed on one and the same line of action. The vector of the mass moment torque is directed perpendicular to the crank drive axis. There, the size of the moment of inertia is determined from the product of the force of inertia engaging in the center of gravity of the roller mill and its vertical distance relative to the engagement point of the centrifugal force of the mass MA.
German Patent DE No. 3,613,036 teaches a drive for a pilger cold-rolling mill. The reference illustrates the action of the various forces on the moving parts of the reference construction.
According to the invention, an optimum mass balancing is only possible if the moment of inertia recited above is eliminated.